ADAMTS-13 Inhibitor

The ADAMTS-13 inhibitor is a chromogenic ELISA assay for the quantification of ADAMTS-13 inhibitor activity.
Clinical details: 
The ADAMTS 13 inhibitor ELISA is a test for detection of human autoantibodies (IgG) in plasma against ADAMTS 13, the protease which is responsible for cleaving unusually large vWF (ULvWF). Most of these autoantibodies inhibit ADAMTS-13 activity and thus non-cleaved ULvWF accumulates in plasma. This is believed to be the major cause for thrombotic thrombocytopenia purpura (TTP). The ADAMTS 13 inhibitor assay makes it possible to differentiate between congenital (gene polymorphisms) and acquired (autoantibodies) TTP when coupled to an activity assay and to control efficacy of plasma exchange therapy
Reference range: 

Negative: <10.0 U/mL

Borderline: 10 - 15 U/mL        

Positive:>15 U/mL

Sample type and Volume required: 
External requests: Citrated platelet poor plasma 500µl x 1 aliquot.
Internal requests: please refer to EPR label
Turnaround time: 
7-14 working days.
Special sample instructions: 

The sample should be analysed or processed & stored within 4 hours of venepuncture. Please ensure sample tubes are filled exactly to the fill-line as underfilling or overfilling creates a dilution error and leads to inaccurate results.

Storage and transport: 
It is advised that citrated plasma is frozen prior to transport and sent to the laboratory on dry ice to maintain sample quality and integrity.
Diagnostic Haemostasis and Thrombosis Department
St Thomas': 020 7188 2797; Guy's: 020 7188 7188 ext. 53860
St Thomas' Hospital
North Wing - 4th and 5th Floors
Westminster Bridge Road
London SE1 7EH

Laboratory opening times

Guy's Hospital
Southwark Wing - 4th Floor
Great Maze Pond
London SE1 9RT

Outside core hours, contact Duty Haemostasis Biomedical Scientist
For clinical advice or interpretation of results, please contact the laboratory in the first instance.

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Last updated: 09/07/2021